Substituted 2&#39;-chloro-4&#39;-nitrosalicylanilides



United States Patent 3,388,163 SUBSTITUTED 2'-CHLOR0-4'-NITRO-SALlCYLANILlDES Jack D. Early, Bethesda, Md., and John P. Chupp,Kirkwood, Mo., assignors to Monsanto Company, St. Louis, Mo., acorporation of Delaware No Drawing. Original application Mar. 22, 1966,Ser. No. 536,256. Divided and this application July 13, 1967, Ser. No.653,017 I 7 Claims. '(Cl. 260-559) ABSTRACT OF THE DISCLOSURE Compoundscharacterized by a 2-chloro 4' nitrosalicylanilido nucleus useful asinsecticides.

This application is a division of copending application Ser. No.536,256, filed Mar. 22, 1966, which latter application is acontinuation-in-part of copending application Ser. No. 462,127, filedJune 7, 1965, now abandoned.

This invention relates to new and pesticidally useful substituted2'-chloro-4-nitrosalicylanilides of the formula:

O i-NH- wherein n is an integer from 0 to 1, wherein A is halogen ofatomic weight in the range of 35 to 80 (that is chloro or brorno, butpreferably chloro) wherein E is chloro or, and preferably hydrogen, andwherein R is alkyl containing from 3 to '8 carbon atoms specificallyisopropyl or C tert.a1kyl of the formula:

RI -C 2C1 2x+x wherein R and R" respectively are straight chain (orlinear) alkyl and respectively satisfy the empirical formula C H whereinm is a whole number from 1 to 3, inclusive, and wherein x is an integerfrom 0 to 4, but preferably 0. It is preferred that R be C tert.alkylsuch as tertlbutyl, tert. pentyl, 1,1-dimethyl-n-butyl andl-ethyll-rnethyl-n-propyl. As illustrative of other variants of R are1,1dimethyl-n-pentyl, 1,1-dimethyl-n-hexyl, 1,1-dimethyl-isoamyl,1,1,3,3-tetramethyl-n-butyl, l-ethyl-lmethyl-n butyl and1,1-diethyl-n-butyl.

The compounds of this invention are prepared by reacting substantiallyone mole of a 2-chloro-4-nitroaniline of the formula:

NHg NO:

wherein E has the afore-described significance with substantially onemole of a substituted S-halosalicyclic acid of the formula R OH ( DHHwherein n, A and R have the aiore-described significance in the presenceof from about 0.33 to about 1.0 mole of phosphorus trichloride and aninert organic liquid (e.g. benzene, toluene, xylene, chlorobenzene,dichlorobenzene, chlorotoluene, trichlorobenzene, and the like, andmixtures thereof) at a temperature above the freezing point of thereaction system up to and including the systems boiling point, however,in general the reaction temperature will be in the range of from about60 C. to about 200 C. The substituted 2'-chloro-4'-nitrosalicylanilideend products are solids and are insoluble in water.

As illustrative of the 5 -halosalicylic acid precursors are3-isopropyl-5-chlorosalicylic acid (M.P. 169-170 C.), 3-tert.butyl-5-chlorosalicylic acid (M.P. 220-222 C.), 6-rnethyl-3-tert.butyl-S-chlorosalicylic acid (M.P. 208-211 C.),3-tert.pentyl-5-chlorosalicylic acid (M.P. 195198 C.),6-methyl-3-tert.butyl-5-bromosalicylic acid (M.P. 170173 (3.), 3-(1,1-dimethyl-n-butyl)-5chlorosalicylic acid (M.P. 154.5 C.),3-(l-ethyl-1-methyl-npropyl)-5-chlorosalicylic acid (M.P. 152-154 C.),6- methyl-3-(1,1 dimethyl n butyl)-5-chlorosalicylic acid (M.P.154.5-156 C.), 3-tert.butyl-5-bromosalicylic acid (M.P. 230-231.5 C.),and 3-(1,1,3,3-tetramethyl-nbutyl)-5-chlorosalicylic acid (M.P. 145-147C.). The salicylic acid precursors for these S-halosalicylic acids areeither known materials or readily prepared by initially ortho-alkylatingphenol or m-cresol with the appropriate olefin in accordance with theprocedure of Stroh et al., Angew. Chem, vol. 69, pp. 699-706 (1957) toprovide the substituted phenol HDDH wherein R and n have theafore-described significance (many of these substituted phenols arecommercially available) and then carboxylating with carbon dioxide inthe presence of aqueous sodium hydroxide in accordance with the Schmittmodification of the Kolbe synthesis (German Patents 29,939 and 38,742)and thereafter aciditying the sodium salt so produced. These salicylicacids are readily halogenated in the 5-position thereof employingchlorine or bromine in the presence of glacial acetic acid.

As illustrative of the compounds of this invention and their preparationbut not limitative thereof is the following:

Example I To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged 8.6 parts by weight of3-isopropyl-S-chlorosalicylic acid (M.P. 169- 170" C.) and 55 parts byweight of chlorobenzene. The so charged mass is heated to about 70 C.and thereto is added with agitation 6.9 parts by weight of 2-chloro-4-nitroaniline followed by 2.5 parts by weight of phosphorus trichloridein 55 parts by weight of chlorobenzene. The reaction mass is thenrefluxed (about 135 C.) for five hours. The mass is then cooled to about70 C. whereupon and with agitation is added 50 parts by weightof waterfollowed by 50 parts by weight of 20 percent hydrochloric acid. Theorganic layer is separated and washed first with water then with diluteaqueous sodium bicarbonate and finally with water. The so washed organicmass is then stripped of volatiles under vacuum. The residue uponrecrystallization from benzene gave3-isopropyl-2',5-dichloro-4-nitrosalicylanilide, M.P. 120-121 C.

Other illustrative examples of the compounds of this invention (ExamplesII to XII-I below) as well as certain homologs, isomers and analogsthereof (Examples A to M below) for purposes of demonstrating thisinvention prepared by the same procedure as in Example I butsubstituting the appropriate substitute salicylic acid and appropriatesubstituted aniline in the same molecular proportions are summarized intabular form below:

Example No.:

II. 3-tert.butyl-2,5-dichloro-4'-nitrosalicylanilide (M.P. 159160 C.)

III. 6-methyl-3-tert.butyl-2',5-dichloro-4'-nitrosalicylanilide (M.P.153-155 C.)

IV. 3-tert.pentyl-2',5-dichloro-4-nitrosalicylanilide (M.P. 136137 C.)

V. 6-methyl-3-tert.pentyl-2',5-dichloro-4-nitrosalicylanilide (M.P.108.5110.5 C.)

VI. 6-methyl-3-tert.butyl-2-chloro-5-bromo-4-nitrosalicylanilide (M.P.170173 C.)

VII. 3-(1,l-dimethyl-n-butyl)-2,5-dichloro-4'-nitrosalicylanilide VIII.3-(l-ethyl-l-methyl-n-propyl)-2',5-dichloro-4- nitrosalicylanilide (M.P.143- l43.5 C.)

IX. 6-methyl-3-(1,l-dimethyl-n-butyl)-2',5-dichl0ro-4-nitrosalicylanilide (M.P. 78-8l C.)

X. 6-methyl-3-tert.butyl-2,5,5-tricl1loro-4'-nitrosalicylanilide (M.P.138.5-140 C.)

XI. 3-tert.butyl-2',5,5-trichloro-4'-nitrosalicylanilide (M.P. 208.5-2l0C.)

XII. 3-tert.butyl-2-chl0ro-5-bromo-4'-nitrosalicylanilide (M.P.172.5174.5 C.)

XIII. 3-(1,1,3,3-tetramethyl-n-butyl)-2,5-dichloro-4-nitrosalicylanilide (M.P. 146148 C.)

A. 2,5-dichloro-4-nitrosalicylanilide (US. 3,147,300)

B. 3methyl-2',5-dichloro-4-nitrosalicylanilide (M.P.

C. 3-ethyl-2',5-dichloro-4'-nitrosalicylanilide (M.P.

D. 3-tert.pentyl-2',5-dichloro-4-bromosalicy1anilide (M.P. 144144.5 C.)

E. 3-tert.butyl-2,5-dichloro-4-bromosalicylanilide (M.P. 168169' C.)

F. 3-tert.butyl-4',5-dichloro-2-nitrosalicylanilide (M.P.

G. 6-methyl-3-tert.butyl-2',5-diehloro-5'-nitrosalicylanilide (M.P.135137 C.)

H. -tert.butyl-2',3-dichloro-4-nitrosalicylanilide (M.P. 220223 C.)

I. 3-tert.butyl-3,5-dichloro-4'-nitrosalicylanilide (M.P.

K. 3-tert.butyl'2,5-dichloro-5-nitr0salicylanilide (M.P.

L. 2,3,5-trichloro-4'-nitrosalicylanilide (M.P. 229- M.5-(1,1,3,3-tetramethyl-n-butyl)-2',3-dichloro-5'- nitrosalicylanilide(M.P. 157-158 C.)

Although the salicylanilides of this invention are useful per se indestroying a variety of pests, it is preferable that they be supplied tothe pests or to the environment of the pests in a dispersed form in asuitable extending agent. The exact concentration of the salicylanilidesof this invention employed in destroying pests can vary considerablyprovided the required dosage (i.e. toxic or pesticidal amount) thereofis supplied to the pests or to the environment of the pests. When theextending agent is a liquid or mixture of liquids (e.g. as in solutions,suspensions, emulsions, or aerosols) the concentration of thesalicylanilide employed to supply the desired dosage generally will bein the range of 0..001 to 50 percent by weight. When the extending agentis a semi-solid or solid, the concentration of the salicylanilideemployed to supply the desired dosage generally will be in the range of0.1 to 25 percent by weight. From a practical point of view, themanufacturer must supply the user with a low cost concentrate or spraybase or particulate solid base in such form that, by merely mixing withwater or finely divided inert solid extender (e.g. powdered clay ortalc) or other low cost material available to the user at the point ofuse, he will have an easily prepared pesticidal spray or particulatesolid. In such a concentrate composition, the

salicylanilide generally will be present in a concentration of 5 to 95percent by weight, the residue being any one or more of the well knownpesticidal adjuvants, such as the surface-active clays, solvents,diluents, carrier media, adhesives, spreading agents, humectants, andthe like, but particularly a finely divided solid extender.

There are a large number of organic liquids which can be used for thepreparation of solutions, suspensions or emulsions of thesalicylanilides of this invention. For example, isopropyl ether,acetone, methyl ethyl ketone, octanone, dioxane, cyclohexanone, carbontetrachloride, ethylene dichloride, tetrachloroethane, hexane, heptaneand like higher liquid alkanes, hydrogenated naphthalenes, solventnaphtha, benzene, toluene, xylene, petroleum fractions (e.g. thoseboiling almost entirely under 400 F., and having a flash point aboveabout F., particularly kerosene), mineral oils having an unsulfonatableresidue above about 80 percent and preferably above about percent. Inthose instances wherein there may be concern about the phytotoxicity ofthe organic liquid extending agent a portion of same can be replaced bysuch low molecular weight aliphatic hydrocarbons as dipentene,diisobutylene, propylene trimer, and the like or suitable polar organicliquids such as the aliphatic ethers and the aliphatic ketonescontaining not more than about 10 carbon atoms as exemplified byacetone, methyl ethyl ketone, diisobutyl ketone, dioxane, isopropylether, and the like. In certain instances, it is advantageous to employa mixture of organic liquids as the extending agent, e.g. an aromatichydrocarbon and an aliphatic ketone.

When the salicylanilides of this invention are to be supplied to thepests or to the environment of the pests as aerosols, it is convenientto dissolve them in a suitable solvent and disperse the resultingsolution in dichlorodiiluoromethene or like chlorofluoroalkane whichboils below room temperature at atmospheric pressure.

The salicylanilides of this invention are preferably supplied to thepests or to the environment of the pests in the form of emulsions orsuspensions. Emulsions or suspensions are prepared by dispersing thesalicylanilides of this invention either per se or in the form of anorganic solution thereof in water with the aid of a water-solublenon-ionic or anionic or cationic surfactant or mixtures thereof. Theterm surfactant as employed here and in the appended claims is used asin Volume II of Schwartz, Perry and Berchs Surface Active Agents andDetergents (1958, Interscience Publishers, Inc., New York) in place ofthe expression emulsifying agent, to connote generically the variousemulsifying agents, dispersing agents, wetting agents and spreadingagents that are adapted to be admixed with the active compounds of thisinvention in order to secure better wetting and spreading of the activeingredients in the water vehicle or carrier in which they are insolublethrough lowering the surface tension of the water (see also Frear,Chemistry of Insecticides, Fungicides and Herbicides, second edition,page 280). The surfactants contemplated are the wellknown capillaryactive substances which are non-ionic or anionic or cationic and whichare described in detail in Volumes I and II of Schwartz, Perry andBerchs Surface Active Agents and Detergents (1958, IntersciencePublishers, Inc., New York), and also in the November 1947 issue ofChemical Industries (pages 811824) in an article entitled, SyntheticDetergents, by John W. McCutcheon and also in the July, August,September and October 1952 issues of Soap and Sanitary Chemicals underthe title Synthetic Detergents. The disclosures of these articles withrespect to non-ionizing capillary active substances are incorporated inthis specification by reference in order to avoid unnecessaryenlargement of this specification. The preferred surfactants are theWater soluble anionic and non-ionic surface active agents set forth inUS. 2,846,398 (issued August 5, 1958).

The salicylanilides of this invention can be dispersed by suitablemethods (e.g. tumbling or grinding) in solid extending agents either oforganic or inorganic nature and supplied to the pests environment inparticulate form. Such solid materials include for example, tricalciumphosphate, calcium carbonate, koalin, bole, kieselguhr, talc, bentonite,fullers earth, pyrophillite, diatomaceous earth, calcined magnesia,volcanic ash, sulfur and the like inorganic solid materials, and includefor example, such materials of organic nature as powdered cork, powderedwood, and powdered walnut shells. The preferred solid carriers are theadsorbent clays, e.g. bentonite. These mixtures can be used forpesticidal purposes in the dry form, or by addition of water-solubleanionic or cationic or non-ionic surfactants the dry particulate solidscan be rendered wettable by water so as to obtain stable aqueousdispersions or suspensions suitable for use as sprays.

-For special purposes the salicylanilides of this invention can bedispersed in a semi-solid extending agent such as petrolatum With orwithout the air of solubility promoters and/or surfactants.

In all of the forms described above the dispersions can be providedready for use in combatting pests or they can be provided in aconcentrated form suitable for mixing with or dispersing in otherextending agents. As illustrative of a particularly useful concentrateis an intimate mixture of a salicylanilide of this invention with awater-soluble anionic or non-ionic surfactant or mixtures thereof whichlowers the surface tension of water in the weight proportions of 0.1 to15 parts of surfactant with sufficient of the salicylanilide of thisinvention to make 100 parts by weight. Such a concentrate isparticularly adapted to be made into a spray for combatting variousforms of pests by the addition of water thereto. As illustrative of sucha concentrate is an intimate mixture of 20 parts by weight of3-tert.phenyl-2',S-dichloro- 4-nitrosalicylanilide and 2 to 4 parts byweight of a water-soluble non-ionic surfactant such as thepolyoxyethylene derivatives of C alkyl substituted phenols such asnonylphenol or dodecylphenol.

Another useful concentrate adapted to be made into a spray forcombatting pests is a solution (preferably as concentrated as possible)of a salicylanilide of this invention in an organic solvent therefor.The said liquid concentrate preferably contains dissolved therein aminor amount (e.g. 0.5 to percent by weight of the weight of the newpesticidal agent) of a non-ionic or anionic surfactant, which surfactantis also water-soluble. As illustrative of such a concentrate is asolution of 3-tert. pentyl-2,5-dichloro-4'-nitrosalicylanilide in amixture of xylene and 2-octanone which solution contains dissolvedtherein a water-soluble non-ionic surfactant such as the polyoxyethylenederivatives of C alkyl substituted phenols such as nonylphenol anddodecylphenol.

In all of the various dispersions described hereinbefore for pesticidalpurposes, the active ingredient can be one or more of thesalicylanilides of this invention. The salicylanilides of this inventioncan also be advantageously employed in combination with otherpesticides, including, for example, nematocides, bactericides, andherbicides. In this manner it is possible to obtain mixtures which areeffective against a wide variety of pests and otherforms of noxiouslife.

In the destruction of pests the salicylanilides of this invention eitherper se or compositions comprising same are supplied to the pests or totheir environment in a toxic or pesticidal amount. This can be done bydispersing the new pesticidal agent or pesticidal composition comprisingsame in, on or over an infested environment or in, on or over anenvironment the pests frequent, e.g. agricultural soil or other growthmedia or other media attractable to the pests for habitational orsustenance or propagational purposes, in any conventional fashion whichpermits the pests to be subject to the pesticidal action of thesalicylanilides of this invention. Such dispersing can be brought aboutby applying sprays or particulate solid compositions to a surfaceinfested with the pests or attractable to the pests, as for example, thesurface of an agricultural soil or other habitat media such as the aboveground surface of host plants by any of the conventional methods, egpower dusters, boom and hand sprayers, and spray dusters. Also forsub-surface application such dispersing can be carried out by simplymixing the new pesticidal agent per se or pesticidal spray orparticulate solid compositions comprising same with the infestedenvironment or with the environment the pests frequent, or by employinga liquid carrier for the new pesticidal agent to accomplish sub-surfacepenetration and impregnation therein.

The salicylanilides of this invention, especially those of the foregoingformula wherein R is C tert. alkyl, are insecticidally active. Toillustrate their activity but not limitative thereof the followinginsecticidal evaluations were employed:

(a) Mosquito (larvae).A base solution of the salicylanilide to beevaluated (itemized in Table I) is prepared by dissolving 0.1 gramthereof in sufficient acetone to provide a 1.0% by weight solution ofthe salicylanilide. 0.05 ml. of this solution is pipetted into each ofthree 25 X 200 mm. culture tubes which respectively contained suflicientdistilled water to provide concentrations in parts per million (p.p.m.)of 10, 2 and 0.2 of the salicylanilide. Each tube is stoppered with anacetone washed rubber stopper and shaken vigorously to facilitatecomplete mixing. Thereupon approximately 25 early instar yellow fevermospuito larve (Aedes aegypti) are transferred to each one of the tubeswith the aid of a pipette. The larvae are then held in the respectivetubes at room temperature for 24 hours at which time mortalityobservations are taken. The results (based on an average of threereplicates of approximately 25 larvae per salicylanilide) obtained areset forth in Table I in percent larvae killed at the respectiveconcentrations of 10, 2 and 0.2 parts per million:

(b) Plum curculio (adult).Respective solutions of the salicylanilide tobe evaluated (itemized in Table I) are prepared by dissolving same insufiicient acetone to provide respective concentrations of thesalicylanilide of 10 and 1 micrograms per microliter. One microliter ofone of these solutions via a microinjection apparatus is applieddirectly to the ventral side of the abdomen of each of 10 adult plumcurculio (Conotrachelus nenuphar), and one microliter of the othersolution via a microinjection apparatus is applied to the ventral sideof the abdomen of each of 10 other adult plum curculio (Conolnachelusnenuphar). After the application each insect is released withinobservation dishes and held for 24 hours at room temperature at whichtime mortality observations are taken. The results (based on an averageof two replicates of 10 insects per salicylanilide) obtained are setforth in Table I in percent adult killed at respective concentrations inmicrograms per adult of 10 and 1:

(c) Housefly (adult).A base solution of the salicylanilide to beevaluated (itemized in Table I) is prepared by dissolving 0.10 gram ofthe salicylanilide in 10 ml. of acetone. To respective portions of thissolution is added suificient distilled water containing 0.01% by weightof isooctylphenyl polyethoxyethanol nonionic surfactant to providemixtures having respective concentrations of the salicylanilide of 10and l micrograms per microliter. One microliter of one of these mixturesvia a microinjection apparatus is applied directly to the thorax of eachof 5 adult female housellies (M. domestica) individually placed in 5plastic tubes, and one microliter of the other mixture via amicroinjection apparatus is applied directly to the thorax of each of 5other adult female houseflies (M. domestica) individually placed in 5plastic tubes. After the application the insects are held in the plastictubes at room temperature for 24 hours at which time mortalityobservations are taken. The results (based on an average of 5 insectsper salicylanilide) are TAB LE I acetone, can be applied to the bark oftrees, shrubs, and the like beneath which these insects gather. Othersalicyl- Mosquito larvae, percent killed at a Housefly, percent killledPlum curculio, percent cone. in p.p.m. oiat a cone. in micrograms killedat a cone. in microper adult 01- grams per adult of- Cpd. of Ex Thesalicylanilides of this invention are particularly useful in coinbattingmembers of the order of insect life Homoptera which includes aphids andthe like, which cause considerable agricultural and horticultural damageand as illustrative of such insecticidal properties of thesalicylanilides of this invention as compared to analogues thereof isthe following:

(d) 10 adult pea aphids (Macrosiphum pisi) are placed on leaves ofgrowing pea plants initially sprayed with an aqueous dispersion of thesalicylanilide to be evaluated having a concentration in percent byweight as set forth in Table II (this dispersion is prepared bydissolving in 10 ml. of acetone suflicient of the salicylanilide to makea 1.0% by weight solution thereof to which solution is added based onthe weight of the solution 0.02% of isooctylphenyl polyethoxyethanolnonionic surfactant and thereafter is added sufficient distilled waterto give the concentration as set forth in Table II). 48 hours afterspraying mortality observations are taken. The results (based on anaverage of two replicates of 10 insects per salicylanilide) for eachsalicylanilide are set forth in Table II:

TABLE II Percent Kill at a Gene. in

In combatting members of the insect order Homoptera elfectively thesalicylanilides of this invention are applied to growing plants, e.g. byspraying the foliage with an aqueous dispersion containing from about0.01 to about 1.0 percent by weight of the salicylanilide, whichdispersion will usually contain based on the salicylanilide from 1 to 15percent by weight of a non-ionic emulsifier. The amount of the aqueousdispersion usually employed will be that which completely wets theleaves of the plant. Greater or lesser concentrations can be useddepending upon the particular insect of this order which is to becombatted, variations in spraying techniques, weather conditions and thelike. During the dormant period, such as during the winter time, asalicylanilide of this invention in the form of a solution thereof, asfor example in anilides of this invention which are also highlyeffective in combatting members of the insert order Homoptera includethe respective salicylanilides of Examples VI, VII, X and XII. Each ofthese compounds exhibited an LD (that is the concentration in microgramsper insect giving a 50% kill) of less than 0.02 microgram per pea aphidemploying in substance the insecticidal evaluation procedure of (d)above. In contrast employing the same procedure the salicylanilides ofExamples A and B respectively exhibited an LD of greater than 0.1microgram per pea aphid.

The salicylanilides of this invention are elfective against thestrawberry spider mite (T ezranychus atlanticus). For example 3-tert.pentyl-Z',5-dichloro-4'-nitrosalicylanilide (the compound of Example IV)exhibited on LD of 0.07 microgram per adult mite on contact therewithwhereas in contrast employing the same procedure the salicylanilides ofExamples A and B respectively exhibited an LD of greater than 0.1microgram per adult mite on contact therewith.

The salicylanilides of this invention are also effective in combattingthe Mexican bean beetle (Epilachna varivestis). For example in asystemic insecticidal evaluation each of the salicylanilides of ExamplesII, III, IV, VI, VII, X and XII exhibited an L'D in the range of 0.07 to0.0025 microgram per adult whereas in contrast in the same systemicinsecticidal evaluation the salicylanilides of Examples A and Brespectively exhibited an LD of greater than 0.1 microgram per adult.

The salicylanilides of this invention are also effective in combattingsouthern armyworm larvae (Proaenia eridania). For example at aconcentration of 10 microgram per larva when applied to lima bean leavesinfested with this larvae kills were observed employing thesalicylanilides of Examples II to XIII inclusive.

In a feeding insecticidal evaluation the salicylanilides of Examples IIand IV exhibited elfective control of the cotton boll weevil.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A substituted 2'-chloro-4-nitrosalicylanilide of the formula whereinn is an integer from to 1, wherein A is halogen of atomic weight in therange of 35 to 80, wherein E is selected from the group consisting ofhydrogen and chloro, and wherein R is of from 3 to 8 carbon atoms and isselected from the group consisting of isopropyl and C tert. alkyl of theformula wherein R and R" respectively are straight chain alkyl of theformula C I-I wherein m is a whole number from 1 to 3, and wherein x isan integer from zero to 4.

2. A compound of claim 1 wherein A is chloro', wherein E is hydrogen,wherein R is of from 4 to 6 carbon atoms and is C tert. alkyl, andwherein x is zero.

3. A compound of claim 1 which compound is 3-tert.buty1-2',5-dichloro-4'-nitrosalicylanilide.

4. A compound of claim 1 which compound is 3-tert.pentyI-2',5-dich1oro-4'-nitrosalicylanilide.

References Cited UNITED STATES PATENTS 3,147,300 9/1964 Schraufstaltteret a1. 260559 FOREIGN PATENTS 233,575 5/ 1964 Austria. 966,074 8/1964Great Britain. 356,756 10/ 1961 Switzerland.

OTHER REFERENCES Schraufstatter et a1.: Zeit. Natturforsch, vol. 16B,pages -108 (1961).

M. S. MILESTONE, Primary Examiner.

N. TROUSOF, Assistant Examiner.

